AES E-Library

AES E-Library

Binaural Response Synthesis From Center-Of-Head Position Measurements for Stereo Applications

In two-channel or stereo applications, such as for televisions, automotive infotainment, and hi-fi systems, the speakers are typically placed substantially close to each other. The sound field generated from such a setup creates an image that is perceived as monophonic while lacking sufficient spatial ``presence'. Due to this limitation, a stereo expansion technique may be utilized to widen the soundstage to give the perception to listener(s) that sound is origination from a wider angle (e.g., +/- 30 degrees relative to the median plane) using head-related-transfer functions (HRTF's). In this paper, we present a method to synthesize responses at a listener¡¦s ears given simply two room-response measurements, where each measurement is obtained between a speaker, in a stereo speaker setup, and an assumed center-of-head position (where the listener is assumed to be seated). The binaural response synthesis approach uses head-shadowing models (for inter-aural intensity differences) and the Woodworth-Schlosberg delay model. This approach is useful when dummy heads are not readily available for HRTF measurements as well as to generalize the approach to reflect measurements that would have been obtained over a large corpus of data (viz., human subjects). We also compare the responses obtained from this approach with measurements done with a dummy-head as well as a few human subjects.